Heavy machinery and equipment used in mining and other like industries often have large diameter tires, some as large as 10 feet in diameter or more, pressurized up to 110 psi or more, as well known to those skilled in the art. When a tire needs servicing, or when the machinery or equipment requires servicing where a tire must be removed first, the tire needs to be deflated before service personnel can perform the service work. If the tire is part of a dual-tire configuration, the tire requiring servicing needs to be deflated to a safe level, such as atmospheric pressure, before work can commence whereas the other tire of the dual configuration also needs to be deflated to a safe level although not all the way to atmospheric pressure. Industry practice dictates that a pressure level of 20 psi in the tire not being worked on in a dual configuration is sufficient to provide a safe environment for service personnel but maintains enough pressure in the tire not being worked on to prevent the bead seal of the tire on the rim from breaking loose, which can add time to the carrying out of the repairs or servicing.
To deflate such large tires, it is known to use a valve core extraction tool that attaches to the valve stem on the tire and permits the removal of the valve core, which is contained in the extraction tool. The extraction tool comprises an exit port that allows the pressurized air in the tire to escape through the exit port when the valve core is removed from the valve stem. The problem with this system is that the time deflate a 10 feet diameter tire having an operation pressure of 110 psi is, on average, 27 minutes or so to a safe pressure before service personnel can work on the tire. It is known that the rate of deflation is a function of the pressure differential between the internal tire pressure and atmospheric pressure. In other words, the rate of deflation is higher when the valve core is removed but as the air pressure in the tire decreases, the rate of deflation of the tire decreases. When the tire is used on mining equipment that generates revenue in the order of approximately $4,000.00 per hour, any unnecessary delay in the servicing of the equipment can result in large amounts of lost revenue for the mining operator.
It is, therefore, desirable to provide an apparatus and method for deflating tires that can decrease the deflation time of tires used on heavy machinery and mining equipment.